Backplane optical connectors are made of a few basic components. A backplane adaptor can hold one or more optical connectors, and is passive in the system's backplane. A daughter card adaptor can also hold one or more optical connectors, and is inserted into the system with the daughter card. The optical connector can include i) an optical ferrule, which provides accurate alignment of the optical fibers interface surface, ii) optical fibers, and iii) a connector assembly, which is a carrier for the ferule, and allows connection to another connector.
When inserting the daughter card inside the system the backplane adaptor “receives” the daughter card adaptor. The backplane adaptor and the daughter card adaptor align with each other. All optical connectors inside the adaptors also align, and therefore ferrule face contact pressure is achieved. Both adaptors latch to one another in a certain force, which can vary with different connectors because different ferrules require different optimal face pressures.
After latching, the adaptor can float to release the forces from the daughter card allow electrical connectors to engage.
Backplane optical connectors usually have two independent mechanisms: an optical latch mechanism and a float mechanism. The optical latch mechanism is used to lock two optical connector ferrules of the optical connector in a correct position against a constant load. The performance of the optical connector ferrule depends on the surface contact force when the ferrule is connected. The latching mechanism ensures constant force when the two ferrules are locked.
The float mechanism is used to address mounting tolerances in backplane optical connectors. Additionally, the float mechanism can isolate the optical mate force in the connector from the backplane and the daughter card printed circuit board (“PCB”). This isolation assures endurance of the system. Isolating the force from the daughter card, results in the card injectors also being isolated from the force.
Connecting a fiber optics connector requires a mate force between the ferrule faces and also guidance between the connectors to enable alignment between the ferrules. During an insertion, an optical connector can self-align without any additional manual operation. The alignment is based on the relative position of the backplane adaptor and the daughter card adaptor, which is rigidly connected to the daughter card. When the daughter card is inserted into the system, it is desirable to have sufficient guidance to allow mate between the backplane adaptor and the daughter card adaptor. However, connecting multiple optical connectors on the same daughter card requires a float to ensure that all optical connectors are mated.
A float mechanism which is embedded in the backplane optical connector has major limitations. Since the backplane connector is limited in physical dimensions (area and volume), when the float mechanism is embedded in the backplane optical connector, it has to be as small as possible and manufactured under very strict tolerances in order to work. The area and volume limitations further prohibit the use of friction lowering devices such as ball bearings. This results in complicated and expensive designs. Another limitation of an embedded float mechanism is that every connector has a limited float stroke.
Therefore, there is a need for a float mechanism that is outside of the backplane optical connector. Such a float mechanism can have manufacturing tolerances which can be less strict, when compared to embedded float mechanisms. An additional advantage of a float mechanism that operates outside of the backplane optical connector is that it can be implemented in connection with any “Push-in, Pull out” connector, which further allows additional flexibility.
Such a float mechanism can achieve a better controlled float, since it is possible to implement ball bearings, springs, cantilevers or any other solution that can not fit inside a standard connector. Further it allows different strokes for the same connector, resulting in a more flexible system and that further allows connectivity of multiple optical connectors.
Such a float mechanism can be separated from the optical connectivity mechanism, in terms of alignment and latch. This allows additional flexibility to the connectors that can be used.